progressive collapse in opensees

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moshtagh
Posts: 18
Joined: Mon Oct 03, 2011 1:23 am
Location: urmia

progressive collapse in opensees

Post by moshtagh » Thu Aug 02, 2012 10:42 am

hi every bodi
does any body have cods about progressive collapse?
its aboute remove a member and analuse the structure
any body can help me?

yas
Posts: 49
Joined: Wed Mar 06, 2013 11:51 pm

Re: progressive collapse in opensees

Post by yas » Mon Mar 11, 2013 8:55 pm

hi
I need progressive collapse codes too. if anyone have some information about this or have a file,please help me.
thanks

vesna
Posts: 3033
Joined: Tue May 23, 2006 11:23 am
Location: UC Berkeley

Re: progressive collapse in opensees

Post by vesna » Wed Mar 13, 2013 6:14 pm

To remove a member you can use remove element command: http://opensees.berkeley.edu/wiki/index ... ve_Command

For this to work you need to remove all recorders and load patterns associated with this element.

yas
Posts: 49
Joined: Wed Mar 06, 2013 11:51 pm

Re: progressive collapse in opensees

Post by yas » Sat Mar 16, 2013 12:17 am

thanks for your helping,but I have some problems again.after introducing sections and material of the frame,I should import the loads and earthquake records,then determining kind of analysis,after that removing the element and determining the period of time we need to omit that ,then imposing the axial load of that removing element to other elements of the bay.then analyzing the frame with the past record of earthquake.are these steps true??
I have some questions too.my model is an steel frame with eccentrically braces.there is hinged connection where braces have connected to beams.so their beams has been divided to three elements.now should I import mass and load forces to the nodes of every three elements separately ?
I appreciate in advance.

vesna
Posts: 3033
Joined: Tue May 23, 2006 11:23 am
Location: UC Berkeley

Re: progressive collapse in opensees

Post by vesna » Mon Mar 18, 2013 8:57 am

I am not sure I understand your question. Would you please restate it?

Note: if your remove the element, nodes are still there. If you only had nodal loads, there is no need to modify this load after you remove the element.

yas
Posts: 49
Joined: Wed Mar 06, 2013 11:51 pm

Re: progressive collapse in opensees

Post by yas » Sat Mar 30, 2013 11:23 pm

hi
Thanks for your paying attention to my question vesna.Its based on progressive collapse guidelines that when you remove an element you must import It,s loads to other elements of that bay.and now I have some problems with orders of that and I don,t know how to introduce the time history file for it,s analyzing?Should I make a file in seismosignal like Sap or not?

vesna
Posts: 3033
Joined: Tue May 23, 2006 11:23 am
Location: UC Berkeley

Re: progressive collapse in opensees

Post by vesna » Sat Apr 06, 2013 10:09 am

If you have element loads on the elements you are removing, after you remove elements and the element load define nodal loads that correspond to that load.

yas
Posts: 49
Joined: Wed Mar 06, 2013 11:51 pm

Re: progressive collapse in opensees

Post by yas » Mon Apr 15, 2013 11:35 am

hi dear vesna
for removing columns in progressive collapse based on GSA or UFC guidelines, Should I write an algorithm for that ?
I mean introduce a hinge for that column and compare displacement of that column with allowable amount?
thanks

yas
Posts: 49
Joined: Wed Mar 06, 2013 11:51 pm

Re: progressive collapse in opensees

Post by yas » Tue Apr 23, 2013 11:40 am

hello
I,m working on progressive collapse analysis of eccentrically braced frames
and could you help me to find an experimental example for my model?
thanks

yas
Posts: 49
Joined: Wed Mar 06, 2013 11:51 pm

Re: progressive collapse in opensees

Post by yas » Tue May 28, 2013 7:49 am

hi everyone
I,m having problem with choosing type of element.I,m working on progressive collapse in eccentrically braced frame and I don,t know use nonlinearBeamColumn or dispBeamColumn for that ? and I also don,t know use fatigue material or steel02 ?

I will appreciate if you help me .

yas
Posts: 49
Joined: Wed Mar 06, 2013 11:51 pm

Re: progressive collapse in opensees

Post by yas » Thu Jun 20, 2013 10:02 am

hello everybody
after removing element in progressive collapse does it need to remove its loads or the loads is removed by removing the element and redistribute the load to the other elements?
thanks in advance

fmk
Site Admin
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Location: UC Berkeley
Contact:

Re: progressive collapse in opensees

Post by fmk » Thu Jun 20, 2013 11:30 pm

if the element has loads applied to it directly, i.e. eleLoads then they must be removed otherwise the program will crash. loads that the element has been transferring to the supports via the load path will be redistribued in the next analysis step (basically on removal the nodes will now be in a state of unbalance which the next analysis step will hopefully be able to sort out!)

yas
Posts: 49
Joined: Wed Mar 06, 2013 11:51 pm

Re: progressive collapse in opensees

Post by yas » Fri Jun 21, 2013 2:37 am

thanks for your reply to my question dear fmk,
in my model the column and the brace I,ve removed doesn,t have ele loads or doesn,t have applied loads directly,so only removing the element is enough,is that true?

fmk
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Joined: Fri Jun 11, 2004 2:33 pm
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Contact:

Re: progressive collapse in opensees

Post by fmk » Fri Jun 21, 2013 3:01 am

yes

yas
Posts: 49
Joined: Wed Mar 06, 2013 11:51 pm

Re: progressive collapse in opensees

Post by yas » Sun Jun 30, 2013 7:30 am

hello everybody
I,m studying about progressive collapse in eccentrically braced frame,and I,ve wrote some codes to remove the elements based on below :

In nonlinear dynamic analyses the gravity loads were linearly increased during 5 s to reach the final values, after that, they were kept unchanged for 2 s to avoid exciting dynamic effects. Once the gravity loads were fully applied at duration of 7 s, one column and connected brace were suddenly
removed, and afterward the subsequent response of the braced frame was investigated.would you please read this and give me some advices to complete it?.specially when gravity loads are kept unchanged for 2 s and I think this part of that is wrong in my codes.

I appreciate in advance



set Factor 1
set dt 0.01

# Total Steps
set Nstep 1000

# First Linear Loading Steps
set InitStep 500

# Number of Constant Load Steps ( Note: Sum of IntStep & ConctStep has to be less than Nstep )
set ConstStep 200

# Remove Element Step ( Note: Smaller than Total Steps )
set RemoveStep 700

# Element to be removed
set RemovedEle1 1
set RemovedEle2 86




################################################

puts " Model Has Been Defined "

source 5story-3bay.tcl

set FileName "data"
file mkdir $FileName


######## Recorders ###########

#### Note: you can not have a recorder for removed element ####


recorder Element -file $FileName/Col3.txt -time -ele 2 globalForce
recorder Element -file $FileName/Col4.txt -time -ele 3 globalForce
recorder Element -file $FileName/Col5.txt -time -ele 4 globalForce


set accelSeries "Series -dt $dt -filePath Elcentro-180_PGA=0.313g-dt0-01-pnt4000.txt -factor [expr $Factor*9.81]"
pattern UniformExcitation 2 1 -accel $accelSeries

set Tot [expr $InitStep+$ConstStep ]


for { set j 1 } { $j <= $Nstep } { incr j 1 } { ;

if { $j <= $InitStep } {


constraints Transformation ;
numberer RCM ;
system SparseGeneral ;
test EnergyIncr 1e-7 25 0 ;
algorithm ModifiedNewton ;
integrator Newmark 0.5 0.25 ;
analysis Transient ;
analyze 1 0.001 ;

}

if { $j > $InitStep } {

if { $j < $Tot } {
constraints Transformation ;
numberer RCM ;
system SparseGeneral ;
test EnergyIncr 1e-7 25 0 ;
algorithm ModifiedNewton ;
integrator Newmark 0.5 0.25 ;
analysis Transient ;
analyze 1 0.001 ;
}

if { $j >= $Tot } {

if { $j < $RemoveStep } {
constraints Transformation ;
numberer RCM ;
system SparseGeneral ;
test EnergyIncr 1e-7 25 ;
algorithm ModifiedNewton ;
integrator LoadControl [expr 1.0/$Nstep] ;
analysis Static ;
analyze 1 ;
loadConst

}

if { $j >= $RemoveStep } {

remove element $RemovedEle1
remove element $RemovedEle2

constraints Transformation ;
numberer RCM ;
system SparseGeneral ;
test EnergyIncr 1e-7 25 0 ;
algorithm ModifiedNewton ;
integrator Newmark 0.5 0.25 ;
analysis Transient ;
analyze 1 0.001 ;
}
}
}
puts "Step is $j"
}


puts " "
puts " "
puts "******************************************************************"
puts "* Multiple Time History Analysis Have Been Performed Succesfully *"

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